Aims: To investigate the natural history of aortic athersclerosis in stroke/TIA patients over a period of 12 months. To identify if vascular risk factors or medication used in stroke/TIA patients (eg: antiplatelet agents) influence the natural history of aortic atheroma. To study the feasibility of a larger study investigating the role of treatment measures that may be used to treat aortic atherosclerosis and prevent stroke/TIA. Study Design and Methodology: This is a prospective blinded 12 month longitudinal sequential Transesophageal Echocardiography (TEE) study of patients with recent stroke/TIA. Patients who have undergone TEE as a part of their stroke work up will be assessed for presence of aortic atherosclerosis (AA). Patients without the initial TEE will be enrolled to undergo their initial TEE assessment for AA. All enrolled patients will undergo a second TEE after a 12 month interval. They will be assessed for vascular risk factors and medication history, especially antiplatelets, anticoagulant, estrogens and hypohipdomic agents. The TEE assessment of AA recorded on videotapes will be digitized to make the following measurements a) maximal thickness, b) plaque area c) plaque burden d) evidence of heteroechogenicity, ulceration and mobility. The measurements will be made in similar locations in the ascending arch, and descending segments at 12 month intervals to assess for any interval change. Other locations will be examined for any new change. Univariate Fisher's Exact test and Odds ratio computation and Multivariable Multiple Logistic Regression Analysis will be used to study the effect of risk factors and medications on the changes in aortic atheroma noted on the sequential TEEs. OBJECTIVES TO BE ACHIEVED: The above study should answer the following questions in stroke/TIA patients: What is the natural history of AA in the various aortic segments? Do vascular risk factors influence the changes in AA over a period of 12 months? Do medications used in prevention of stroke also prevent the progression of AA? In addition this study should lead to: A standardized method for TEE quantification of AA such as plaque area and plaque burden. Designing of future placebo controlled prospective studies aimed at investigating measures that may be used to treat AA in stroke/TIA patients.